Electrical smelting furnace



April 29. 1924. 1,492,087

J. F. SHAWHAN ELECTRICAL SMELTING FURNACE or inal Filed April is, 1920 r 5 39 l L l 5 W 36 aaa Patented Apr. 29, 1924.

fumes r. snnwnan, or

. S A ES-"PATE T OFFICE.;-"

DAYTON, assienoa or ONE-HALF TOP SAQ B F DAYTON, 0 I I I ELECTRICAL SMELTING summon;

Original application filed April 15, 1920, Serial no. 374,030. Divided as this'application filed February I 10, 1924'. Ser1a1 Fe.'693,505.-

7 To all whom it may concern. i

Be it known that I, JABEA F. snawnamgl a citizen of the United States, and residing 1 at Dayton, State of Ohio,rhave invented the I new and useful Improvementjin Electrical Smelting Furnaces, of which the'following is a specification. I s

This invention relates to smelting furnaces, and more particularly to that typeiof furnace used for smelting pyritic ores. This plication is a divislon of application a s rial Number 37 4,030, filed April 15, 1920.,

In the process of pyritic smelting, the

heatrequired for the smelting process is obll tained by combustion of materialsconta-ined in the ores themselves,particularly sulphur and iron in the case of pyritic ores. In order. to carry on such a process, pure air in a heated conditionniust be suppliedto the char e. to cause oxidation of the sulphur and non. The char e can, of course,-first be brou ht toa s ciently; 'high temp'eratu'reso t at theokidation will be'carried on automatically-by rapid oxidation of the iron and sulphur, but once this condition has been attained, the process-goes onof itself so long as the propersupplyof heated air'and ore is maintained.

I One of the objects of this invention',;there 30 fore, is to provide a smelting furnace adapted to carr onsuch a smelting process continuously y providing an adequate. supply of properly heated air 11 on the. charge.

Ina great many cases, acilities for smeltt ing by ordinary methods, are not on hand at the mine and ores must beflshippedto adistance to be smelted. As theores in the mine usually carry only about 10% of their weight in valuable metals, a great saving can be effected by carrying on thesmelting operation at the mine, thereby saving, the

cost of transportin the bulky ores and the neces'saryiuelfor eating the air and the charge. i As water powerlis, usually available in minin districts, and when transformed into e ectrical energy,a can beused for heating purposes, this invention provides ,means for carrying on a smelting 1 process'at theminesa Another object of this invention, therefore, is to provide means for utilizing ma terials and sources of ener y'available at or near the mine location or the smelting process; i

Another object of thisinventionis to provide electric means for heating the air used in such aprocess.

f'Further objects will appear from. the detail description taken in connection with the accompanying drawing Whichrepresents a furnace cmat the sides are tuyeres 6. These may be all of the usual construction, the lower part of the furnace, including the crucible, and the smelting chamber are usually-constructed of brick and lined with refractorymaterial,

while the ore stack 1 may be of .cast iron: I

and may be provided" with a waterjacket Sto keep it cool. v

Underneath, the smelting, furnace is a chamber 30 in which are mounted electrodes 33, 34, 35 and 36, adapted toform in this case, twoarcs for heating this chamber. I One, two or; more arcs ma be used, according to circumstances; T ese electrodes pass through ,theiwalls of the chamber and are insulated by bushings of refractory material .37 and 38. The lower electrodes'33and 35 arepro'videdwith. connectors 12 for connectionto the electric circuit. The upperelec- I trodes 34 and: 36 areeach provided with an elevating device "39 such as a rack and inion movement. These electrodes are urther equipped with connectors, not shown, for connection to the circuit.

Surrounding the heating chamber 30 is a series offair passages 40 communicating at the lower end with the air heating chamber 41 and at the upper end with the tuyeres 6. The air sup ly enters the chamber14; at the inlet 42 am? asses through the ducts 43 to the heating 0 amber 41 Where it is heated by contact with the hot electrodes 33 and 35, passingl thence up through the; passages40, ein eatedby contact with the hot walls 44o the heating chamber 30, to thetuyeres 6. Thisarc-heated chamber maybe put to double'use by using it as aJrefining-furnace. To this purpose it may be provided with an inlet 31 and an outlet 32. The material to be operated uponis spread over thefioor. to

be acted upon by the are heat. If said material is a conductor of electric current it may be heated by passing the current directly through it. g

The electrical connections of the furnace to the supply circuit may be made as shown in the drawing. The electrodes are connected through the double throw switch 45 to the secondary of an adjustable transformer $6 connected to the supply line. lVith this arrangement, the furnace can be used either as an arc furnace or as a resistance furnace. By throwing the switch 45 to the upper position, the electrodes 33 and 35 are connected to one side of the circuit and the electrodes 3a and 36 to the other side of the circuit. It is evident that with this connection either or both of the electric furnaces may be used as an arc furnace by touching and separating the electrodes by means of the controlling device 39. It is convenient to use furnace in this way as an arc furnace when starting up on a new charge, as heat can be generated more rapidly. \Vhen the charge has melted down, the switch 4C5 may be thrown to the lower position whereby the electrodes 33 and 35 are connected to opposite sides of the circuit. With this connection, the furnace operates as a resistance furnace establishing a circuit through the molten charge. \Vith this connection, it-is immaterial whether the upper electrodes are or are not in contact with the lower electrodes, since each pair is short circuited by the switch 45.

It will be seen, therefore, that this invention provides a combination smelting and refining furnace which is very effective. The heat generated by the current is applied directly to the material to be heated, so that there is no waste and great economy of operation is, therefore, possible. The arrangement of the furnace chambers and air passages is also such as to conserve all the heat possible, so that additional saving is effected. On account of the easy adjustability of the electric current, the ap lication of heat can be closely regulate and the smelting process can, therefore, be very accurately controlled.

It is obvious that various changes may be made in the details of construction without departing from the spirit of this invention; it is, therefore, to be understood that this invention is not to be limited to the specific details shown and described.

Having thus described the invention, what is claimed is:

1. A pyritic smeltin furnace, comprising, a furnace chamber adapted to receive the charge and provided with tuyeres, means for delivering air to said tuyeres, and an enclosed electric are adapted to heat said air.

2. A pyritic smelting furnace, comprising, a furnace chamber adapted to receive the charge and nrovided with tnyeres, means for delivering air to said tuyeres, and an electric are adapted to heat said air, but out of contact therewith.

3. A pyritic smelting furnace, comprising, a furnace chamber adapted to receive the charge and provided with tuyeres, means for delivering air to said tuyeres, and an electric are adapted to heat said air, without extracting oxygen therefrom.

4. A pyritic smelting furnace, comprising, a furnace chamber adapted to receive the charge and provided with tuyeres, means for delivering air to said tuyeres, and means for heating said air including a heating chamber, an electric are adapted to heat said chamber, and means for circulating said air over the walls of said chamber adapted to heat said air but out of contact with said arc.

5. A pyritic smelting furnace, comprising, a chamber adapted to receive the charge and provided with tuyeres, means for delivering air to said tuyeres, and means for heating said air including a heating chamber, an electric are adapted to heat said chamber, and means for circulating said air over the walls of said chamber adapted to heat said air without extracting oxygen therefrom.

6. A pyritic smelting furnace, comprising, a smeltin chamber adapted to receive a charge an provided with tuyeres, means for delivering air to said tuyeres, and means for heating said air inclu ing an electric arc chamber, and air passages surrounding said chamber and communicating with said tuyeres.

. A yritic smelting furnace, comprising,

a smelting chamber adapted to receive a charge and provided with tuyeres, means for delivering air to said tuyeres, and means for heating said air including an electric arc chamber disposed below said smelting chamher, and air passages surrounding said chamber and communicating with said tuyeres.

8. A pyritic smelting furnace. con'iprising, a smeltin chamber adapted to receive a charge an provided with tuyeres, means for delivering air to said tuyeres, and means for heating said air including an arc-heated refining chamber, and air passages surrounding said chamber and communicating with said tuyeres.

9. A pyritic smelting furnace, comprising, a smelting chamber adapted to receive a charge and provided with tuyeres, means for delivering air to said tuyeres, and means for heating said air including an arc-heated refinin chamber, disposed below said smeltin cham er, and air passages surrounding sai chamber and communicating with said tuyeres.

In testimony whereof I affix my signature this 28 day of February, 1923.

JABEA F/SHAWHAN.

IOU 

